<?php

namespace GetId3\Module\Audio;

use GetId3\Handler\BaseHandler;
use GetId3\Lib\Helper;

/////////////////////////////////////////////////////////////////
/// GetId3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
// See readme.txt for more details                             //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.audio.dts.php                                        //
// module for analyzing DTS Audio files                        //
// dependencies: NONE                                          //
//                                                             //
/////////////////////////////////////////////////////////////////

/**
 * module for analyzing DTS Audio files
 *
 * @author James Heinrich <info@getid3.org>
 *
 * @link http://getid3.sourceforge.net
 * @link http://www.getid3.org
 */
class Dts extends BaseHandler
{
    /**
     * @return bool
     */
    public function analyze()
    {
        $info = &$this->getid3->info;

        // Specs taken from "DTS Coherent Acoustics;Core and Extensions,  ETSI TS 102 114 V1.2.1 (2002-12)"
        // (http://pda.etsi.org/pda/queryform.asp)
        // With thanks to Gambit <macteam@users.sourceforge.net> http://mac.sourceforge.net/atl/

        $info['fileformat'] = 'dts';

        $this->fseek($info['avdataoffset']);
        $DTSheader = $this->fread(16);

        $magic = "\x7F\xFE\x80\x01";

        if (strpos($DTSheader, $magic) === 0) {
            $info['dts']['raw']['magic'] = $magic;
            $offset = 4;
        } else {
            if (!$this->isDependencyFor('matroska')) {
                unset($info['fileformat']);

                return $this->error('Expecting "'.Helper::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.Helper::PrintHexBytes(substr($DTSheader, 0, 4)).'"');
            }
            $offset = 0;
        }

        $fhBS = Helper::BigEndian2Bin(substr($DTSheader, $offset, 12));
        $bsOffset = 0;
        $info['dts']['raw']['frame_type'] = $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['raw']['deficit_samples'] = $this->readBinData($fhBS, $bsOffset, 5);
        $info['dts']['flags']['crc_present'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['raw']['pcm_sample_blocks'] = $this->readBinData($fhBS, $bsOffset, 7);
        $info['dts']['raw']['frame_byte_size'] = $this->readBinData($fhBS, $bsOffset, 14);
        $info['dts']['raw']['channel_arrangement'] = $this->readBinData($fhBS, $bsOffset, 6);
        $info['dts']['raw']['sample_frequency'] = $this->readBinData($fhBS, $bsOffset, 4);
        $info['dts']['raw']['bitrate'] = $this->readBinData($fhBS, $bsOffset, 5);
        $info['dts']['flags']['embedded_downmix'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['flags']['dynamicrange'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['flags']['timestamp'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['flags']['auxdata'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['flags']['hdcd'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['raw']['extension_audio'] = $this->readBinData($fhBS, $bsOffset, 3);
        $info['dts']['flags']['extended_coding'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['flags']['audio_sync_insertion'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['raw']['lfe_effects'] = $this->readBinData($fhBS, $bsOffset, 2);
        $info['dts']['flags']['predictor_history'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        if ($info['dts']['flags']['crc_present']) {
            $info['dts']['raw']['crc16'] = $this->readBinData($fhBS, $bsOffset, 16);
        }
        $info['dts']['flags']['mri_perfect_reconst'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['raw']['encoder_soft_version'] = $this->readBinData($fhBS, $bsOffset, 4);
        $info['dts']['raw']['copy_history'] = $this->readBinData($fhBS, $bsOffset, 2);
        $info['dts']['raw']['bits_per_sample'] = $this->readBinData($fhBS, $bsOffset, 2);
        $info['dts']['flags']['surround_es'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['flags']['front_sum_diff'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['flags']['surround_sum_diff'] = (bool) $this->readBinData($fhBS, $bsOffset, 1);
        $info['dts']['raw']['dialog_normalization'] = $this->readBinData($fhBS, $bsOffset, 4);

        $info['dts']['bitrate'] = self::bitrateLookup($info['dts']['raw']['bitrate']);
        $info['dts']['bits_per_sample'] = self::bitPerSampleLookup($info['dts']['raw']['bits_per_sample']);
        $info['dts']['sample_rate'] = self::sampleRateLookup($info['dts']['raw']['sample_frequency']);
        $info['dts']['dialog_normalization'] = self::dialogNormalization($info['dts']['raw']['dialog_normalization'], $info['dts']['raw']['encoder_soft_version']);
        $info['dts']['flags']['lossless'] = (($info['dts']['raw']['bitrate'] == 31) ? true  : false);
        $info['dts']['bitrate_mode'] = (($info['dts']['raw']['bitrate'] == 30) ? 'vbr' : 'cbr');
        $info['dts']['channels'] = self::numChannelsLookup($info['dts']['raw']['channel_arrangement']);
        $info['dts']['channel_arrangement'] = self::channelArrangementLookup($info['dts']['raw']['channel_arrangement']);

        $info['audio']['dataformat'] = 'dts';
        $info['audio']['lossless'] = $info['dts']['flags']['lossless'];
        $info['audio']['bitrate_mode'] = $info['dts']['bitrate_mode'];
        $info['audio']['bits_per_sample'] = $info['dts']['bits_per_sample'];
        $info['audio']['sample_rate'] = $info['dts']['sample_rate'];
        $info['audio']['channels'] = $info['dts']['channels'];
        $info['audio']['bitrate'] = $info['dts']['bitrate'];
        if (isset($info['avdataend'])) {
            $info['playtime_seconds'] = ($info['avdataend'] - $info['avdataoffset']) / ($info['dts']['bitrate'] / 8);
        }

        return true;
    }

    /**
     * @param  type $bin
     * @param  type $offset
     * @param  type $length
     *
     * @return type
     */
    private function readBinData($bin, &$offset, $length)
    {
        $data = substr($bin, $offset, $length);
        $offset += $length;

        return bindec($data);
    }

    /**
     * @param  type $index
     *
     * @return type
     */
    private static function bitrateLookup($index)
    {
        $DTSbitrateLookup = array(
            0 => 32000,
            1 => 56000,
            2 => 64000,
            3 => 96000,
            4 => 112000,
            5 => 128000,
            6 => 192000,
            7 => 224000,
            8 => 256000,
            9 => 320000,
            10 => 384000,
            11 => 448000,
            12 => 512000,
            13 => 576000,
            14 => 640000,
            15 => 768000,
            16 => 960000,
            17 => 1024000,
            18 => 1152000,
            19 => 1280000,
            20 => 1344000,
            21 => 1408000,
            22 => 1411200,
            23 => 1472000,
            24 => 1536000,
            25 => 1920000,
            26 => 2048000,
            27 => 3072000,
            28 => 3840000,
            29 => 'open',
            30 => 'variable',
            31 => 'lossless',
        );

        return (isset($DTSbitrateLookup[$index]) ? $DTSbitrateLookup[$index] : false);
    }

    /**
     * @param  type $index
     *
     * @return type
     */
    private static function sampleRateLookup($index)
    {
        $DTSsampleRateLookup = array(
            0 => 'invalid',
            1 => 8000,
            2 => 16000,
            3 => 32000,
            4 => 'invalid',
            5 => 'invalid',
            6 => 11025,
            7 => 22050,
            8 => 44100,
            9 => 'invalid',
            10 => 'invalid',
            11 => 12000,
            12 => 24000,
            13 => 48000,
            14 => 'invalid',
            15 => 'invalid',
        );

        return (isset($DTSsampleRateLookup[$index]) ? $DTSsampleRateLookup[$index] : false);
    }

    /**
     * @param  type $index
     *
     * @return type
     */
    private static function bitPerSampleLookup($index)
    {
        $DTSbitPerSampleLookup = array(
            0 => 16,
            1 => 20,
            2 => 24,
            3 => 24,
        );

        return (isset($DTSbitPerSampleLookup[$index]) ? $DTSbitPerSampleLookup[$index] : false);
    }

    /**
     * @param  type        $index
     *
     * @return int|bool
     */
    private static function numChannelsLookup($index)
    {
        switch ($index) {
            case 0:
                return 1;
                break;
            case 1:
            case 2:
            case 3:
            case 4:
                return 2;
                break;
            case 5:
            case 6:
                return 3;
                break;
            case 7:
            case 8:
                return 4;
                break;
            case 9:
                return 5;
                break;
            case 10:
            case 11:
            case 12:
                return 6;
                break;
            case 13:
                return 7;
                break;
            case 14:
            case 15:
                return 8;
                break;
        }

        return false;
    }

    /**
     * @param  type $index
     *
     * @return type
     */
    private static function channelArrangementLookup($index)
    {
        $DTSchannelArrangementLookup = array(
            0 => 'A',
            1 => 'A + B (dual mono)',
            2 => 'L + R (stereo)',
            3 => '(L+R) + (L-R) (sum-difference)',
            4 => 'LT + RT (left and right total)',
            5 => 'C + L + R',
            6 => 'L + R + S',
            7 => 'C + L + R + S',
            8 => 'L + R + SL + SR',
            9 => 'C + L + R + SL + SR',
            10 => 'CL + CR + L + R + SL + SR',
            11 => 'C + L + R+ LR + RR + OV',
            12 => 'CF + CR + LF + RF + LR + RR',
            13 => 'CL + C + CR + L + R + SL + SR',
            14 => 'CL + CR + L + R + SL1 + SL2 + SR1 + SR2',
            15 => 'CL + C+ CR + L + R + SL + S + SR',
        );

        return (isset($DTSchannelArrangementLookup[$index]) ? $DTSchannelArrangementLookup[$index] : 'user-defined');
    }

    /**
     * @param  type    $index
     * @param  type    $version
     *
     * @return bool
     */
    private static function dialogNormalization($index, $version)
    {
        switch ($version) {
            case 7:
                return 0 - $index;
                break;
            case 6:
                return 0 - 16 - $index;
                break;
        }

        return false;
    }
}
